Process of making bis-carbamic acid ester compounds



United States Patent Q PROCESS OF MAKING BIS-CARBAMIC ACID ESTER COMPOUNDS Otto Schmid, Leonding, near Linz, and Ludwig Bilek and Walter Seifricd, Linz, Austria, assignors to Oester- I reichische Stickstoffwerke Aktiengesellschaft, Linz (Donau), Austria, a corporation of Austria No Drawing. Application June 16, 1954 Serial No. 437,272

Claims priority, application Austria June 23, 1953 A 4 Claims. (Cl. 260-482) l\ /R1 H R2NAO.C O.NHBNH.C O. OANR2 .(2X)" I In said formula R R R represent methyl radicals while A is the ethylene radical and B is a polymethylene radical with more than two methylene groups and X is an anionic radical.

The process of producing such compounds according to the present invention consists in condensing the corresponding di-isocyanates of the polymethylene series or compounds which are convertible into such di-isocyanates, with 2-amino alcohols having a tertiary amino group. Thereby .the corresponding di-tertiary bases of the formula are obtained which are then subjected to quaternization at the two tertiary nitrogen atoms.

Organic isocyanates as they are used as starting materials according to the present invention correspond to the following formula:

wherein y is an integer higher than 2. Compounds which are convertible into such di-isocyanates are, for instance polymethylene dicarboxylic acid diazides of the formula.

1-I,.oc. cH,),,.c0.1-1 p or polymethylene dicarbamic acid dichlorides of the formula t J 1 Tetramethylene bis -(car bamic acid-p-dimethylamino ethylt not isat58. c. p t Tetramethylene bis-(carbamic acid choline iodide ester) 5 parts of tetramethylene bis-(carharnic acid-f. -dimethylamino ethyl ester) are dissolved in 8 parts of acetone. 10

The tertiary Z-amino alcohols useful in this reaction correspond to the following formula:

/N.CH2.CH:OH Ra v1 a The resulting bases correspond to the following formula: 3

\ /N--OH|CH|. o.o0-NH-(o In) .-Nn. c o .0.0 Ha.CHa.N\

VII

The tertiary amino alcohol used in this synthesis of.

di-tertiary bases (Formula VII) is dimethylamino ethanol.

Quaternization of said di-tertiary bases of Formula VII is carried out according to the present invention with alkylating agents of the formula R X. Said alkylating agents are, for instance, methyl halogenides, dimethyl sul-1' fate, toluene sulfonic acid esters and the like. There-.

by the quaternary ammonium compounds illustrated by Formula I are obtained t The compounds obtained according to the present invention are valuable pharmaceutical agents and can also be used for pest control. Several of said compounds possess a considerable pharmacological effect of inhibiting the true cholinesterases as well as the pseudocholinesterases. The polymethylene bis-(carbamic acidcholine esters) have a high neurornuscular-blocking effect. Hexamethylene bis-(carbamic acid choline ester), the preparation of which in the form of various crystalline pure salts is described hereinafter in Examples l, 5, and 7, belongs to the most highly and most persistently active synthetic muscle relaxant heretofore known.

The following examples serve to illustrate the present invention without, however, limiting the same thereto.

The amounts given in said examples are expressed inparts by weight.

, EXAMPLE 1 M 3 ester) 9.5 parts of tetramethylene di-isocyanate are mixed,: while cooling, with 14.6 parts of ,B-dimethylamino ethanol. The reaction mixture is allowed to stand at room tempera-,

ture for 24 hours. The resulting crystalline mass is dissolved in 36 parts of acetone.

Thereby a crystalline mass precipitates. Said mass is filtered; off by suction and the crystals are washed with a coldlmixture of acetone and petroleum ether (l:5).[ 19.6 parts of. tetramethylene bis-(carbamic acidqS-di-I methylamino ethyl ester) are obtained in the form of white. crystalline leaflets. of the theoretical yield. The melting point of this prodparts of methyl iodide are added in portions to said solution while cooling. The precipitated oil soon crystallizes. 1 The crystals are filtered off by suction and are recrys tallized from parts of 96% ethanol. Thereby 9:3 parts of said tetramethylene bis-(carbamic acid choline" iodide ester) are obtained in the form of white crystals- Patented Mar. 17, 19 59".

Any undissolved flakes are filtered ofi and petroleum ether (of low boiling point) is added to the clear solution at 0 C. while cooling.

The yield amounts to 91%:

EXAMPLE 2 octamethylene bis-(carbamic acid-,B-dimethylamino ethyl ester) 20.7 parts of p-dimethylamino ethanol are added to and mixed with 15.2 parts of octamethylene diisocyanate while stirring and cooling. 'The mixture is allowed to stand at room temperature'for 24 hours. The resulting crystallized reaction product is dissolved, while heating moderately, in 50 parts of acetone. 200 parts of water are added to said solution and the mixture is allowed to cool. A small amount of slimey fiakes are removed by filtration and theacetone is distilled off by vacuum distillation from the clear filtrate. On cooling, white silky leaflets precipitate. They are filtered ofi? by suction, washed with ice water, and dried. The yield of octamethylene bis-(carbamic acid-p-dimethylamino ethyl ester) amounts to 24 parts corresponding to 83% of the theoretical yield. The melting point of the resulting product. is at 78 C. The above mentioned compound can be obtained with about the same yield by dissolving sebacic acid diazide in chloroform, heating said solution with dimethylamino ethanol, removing the chloroform, and working up the resulting reaction product as described hereinbefore.

octamethylene bis-(carbamic acid choline chloride ester) 4.5 parts of octamethylene bis-(carbamic acid-fi-dimethylamino ethyl ester), obtained as described hereinbefore, are dissolved in 32' parts of acetone. 20 parts of methyl chloride are. added in three portions to said solution while cooling. The mixture is allowed to stand at 0 C. for 10 days. Excess of methyl chloride and the acetone are separated from the precipitated white crystalline mass. The crystals are reprecipitated from alcohol-e'ther (1:11). The resulting crystals are filtered oh by suction, washed with ether, and dried. In this manner 5.2 parts of a white crystal powder having a melting point of 205-208" C. are obtained. The yield corresponds to 91% of the theoretical yield.

EXAMPLE 3 Decamethylene bis-(carbamic acid-B-dimethylamino ethyl ester) off by suction, washed, and dried, and yields about 7.9

parts of said product of a melting point of 77-79 C. 3.6 parts of the same compound can be recovered from the mother liquor. The total yield amounts to 11.5 parts corresponding to 81% of the theoretical yield.

Decamethylene bis-(carbamic acid choline iodide ester) 7.9' parts of decamethylene bis-(carbamic acid-fi-di methylamino ethyl ester) are dissolved in 40 parts of acetone. parts of methyl iodide are slowly added to said solution while cooling and stirring. Thereby an oil precipitates which immediately starts to crystallize. The mixture is allowed to stand for two days. The crystals are then filtered off by suction, washed, and dried. The crude product obtained in this manner in an amount of 13.5 parts is recrystallized from absolute. alcohol. Thereby l-2.9 parts of decamethylene bis-(carbamic acid The yield amounts to 98% of analytical grade white crystals r i i r 4.v

melting at 135-1365 C. Theyield amounts. to 9.6%. of the theoretical yield.

EXAMPLE 4 Hexamethylene bis-(carbamic acid-B-dimethylamino ethyl ester) Hexamethylone bis-(carbamic acid choline chloride ester) 5 parts of hexamethylene bis-(carbamic acid-B-dimethylamino ethyl ester) obtained as described above, are dissolved in 15 parts of methyl ethyl ketone. 6 parts of methyl chloride are added to said solution. The reaction mixture is allowed to stand for several. days. Hex.- amethylene bis(carbamie acid cholinev chloride ester) precipitates first in the form of an oil wltu'ch; gradually crystallizes. The crystalline product, on reprecipitation from methanol-acetone has a melting point of 187 C.

EXAMPLE 5 Hexamethylene bis-(carbamic acid choline bromide. ester).

42 parts of hexamethylene bis(carbamic acid-fl-dimethylamino ethyl ester) obtained according to Example 4, are dissolved in 350 parts of acetone. parts of methyl bromide are added to saidsolution. The reaction mixture is allowed to stand for 24 hours whereby the reaction product precipitates almost quantitatively. The precipitate is recrystallized from ethanol or from a mixture of methanol and acetone. 56.5 parts of hexamethylene bis-(carbamic acid choline bromide ester) are obtained thereby, corresponding to 87% of the theoretical yield. Said compound has a melting point of 174-176 C.

EXAMPLE 6 Hexamethylene bis-(carbamic acid choline iodide ester) 10 parts of hexamethylene bis-(carbamic acid-fi-dimethylamino ethyl ester) obtained. according to. Example 4, are dissolved in 200 parts of methyl ethyl ketonc. 35 parts of methyl iodide are admixed thereto. The re.- action mixture is allowed to stand for 12 hours at room temperature. which mass is recrystallized from a mixture of ethanol and water, for instance, from 96% ethanol whereby the dihydrate of hexamethylene bis-(carbamic acid choline iodide ester) is obtained in almost quantitative yield. Its melting point is at about 118 C. On drying said compound at elevated temperature in a vacuum, it loses its waterof crystallization and melts, in the anhydrous state,

at 173 C.

EXAMPLE 7 Hexamethylene bis-(carbamic acid-fi-dimethylamino ethyl ester-p-toluene sulfonic acid methylate) 5 parts of hexamethylene bis-(carbamic acid-B-dimethylamino ethyl ester) obtained according to Example 4,

and 5.6 parts of p-toluene sulfonic acid methyl ester are dissolved in 25 parts of acetone. The reaction mixture isallowedto stand at room temperature for 48 hours. The

precipitated crystals are filtered off by suction, washed with acetone, and dried. 10 parts of hexamethylene bis- (carbamic acid-B-dimethylamino ethyl ester-p-toluene sulfonic acid methylate) corresponding to 96% of the the oretical yield are obtained thereby. On recrystallization choline iodide ester) are obtained in the form of 76 from methanol and drying at C. in a vacuum, the

A crystalline mass precipitates therebyp 6 I analytical grade compoundhas a melting point of'2S7- readily be mixed with each other without any precipita-" 261 C. tionof the barbiturate. Such precipitation occurs with a Other quaternary ammonium compounds correspond number of other heretofore used muscle relaxants. ing to Formula I given hereinbefore are obtained inlan, The initial dose of hexamethylene bis-(c arbamic acid analogous manner as disclosed in the preceding exam 5 choline bromide ester) 'is'adjusted,'on the one hand,in ples. For instance, when proceeding according to the accordance with the body weight of the patient and, on

above given example, there can be used in place of tetrathe other hand, according to the expected duration of the methylene di-isocyanate equimolecular amounts of other operation.

polymethylene di-isocyanates having up to 10 methylene Clinical. experience has shown that the following initial groups in their molecule. 1' f 1'0 dose yields satisfactory results: In Place Of yl genides there can be used for For operations presumably lasting half an hour to one quaternization reaction dimethylsulfate, sulfonic acid es-' hour, 0.05 mg. to 0.07 mg. of hexamethylene bis-(carters, such as p-toluene sulfonic acid esters, and other bamic acid choline bromide ester) are administered per quaternizing compounds. Y i kg. of body weight.

The quaternary ammonium compounds which are ob Foroperations presumably exceeding aduration of one tained by the process according to the present invention, hour, 0.08 mg. to 0.10 mg. per kg. of body weight areas described in the preceding examples, have interesting. required. a

pharmacological properties and are successfully employed. In most cases one single administration of such a dose in therapy as highly efiective muscle relaxants. Espeis sufiicient to carry out the operation without any apcially valuable are the polymethylen bis-(carbamicacid preciable disturbance. Except in the case of extensive choline ester) compounds ot the following formula operations of long duration it is advisable not to increase 011 1 on. CHQ;NCHs-OHi-O.OO NH-(CH:),NH-C0.0-CHr-CHr-NCHt .21? CH3 CH: wherein Y is an integer higher than 2 and X is an anionic; .-the" dose above 0.10 mg. per kg. of body weight. radical and especially halogen. As stated above, com- The new compounds are usually provided in theform pounds of this type have a surprisingly high neuromus: of isotonic aqueous solutions of their water soluble salts cular activity. containing between about 1 mg. and about 100 mg. perj Maximum neuromuscular paralyzing eifect iso btained' cc with hexamethylene bis-(carbarnic acid choline halogen- The compounds obtained according to the present inide ester) and octamethylene bis-(carbamic' acid'choline vention may also be orally administered, for instance,- halogenide ester). Said compounds proved to be about in the form of tablets, pills, lozenges, drages, and the three times as effective as the known and widely used like preparations. They may furthermore be employed decamethonium halogenide on comparing said drugs in in therapy in the form of powders filled in gelatine captests withnon-narcotized dogs and narcotized cats. These sules and the like. Such preparations are preferably new compounds have the further advantage that, on addiluted with a'suitablecarrier and extending agent.

ministration of larger doses, their neuromuscular paralyz- For instance, when preparing tablets, pills, drages ing elfectis considerably prolonged. and the like, the commonly used'diluting agents, binders, Another very important advantage of said compounds 40 and the like are employed, such as sugar, lactose, talcum,

is that they do not exhibit any ganglionic stimulating starch, bolusalba, pectin, and as binders, gelatin, gum

effect and more particularly do not cause an increase in arabic, methyl cellulose, yeast extract, agar, tragacanth,

blood pressure when applied in doses required for their and others.

neuromuscular paralyzing action. It is, however, an es- We claim:

sential characteristic of the present invention, that the 1. In a process of producing apolymethylene bis-(carcompounds used in therapy must be of highest purity bamic acid choline ester) compound of the formula CH3 CH3 and must be present in the crystalline state. An amorwherein n is an integer from 4 to 10 and X is an anionic phous non-crystalline product is not suitable for theragroup selected from the group consisting of chlorine, peutic purposes apparently due to accompanying bybromine, iodine, and the p-toluene sulfonic acid anion, products. Such an amorphous product produce 011 dthe steps comprising mixing p-dimethylamino ethanol with ministration to patients, nicotine-like side-effects .and a polymethylene diisocyanate having 4 to 1 methylene more particularly increase in blood pressure, accelerated groups, while cooling, allowing the reaction mixture to P and frequently arhythmlas Whlch are very stand at room temperature until condensation is comoblecuonableplete, dissolving the resulting polymethyllene bis-(car- Clinical tests have been carried out, for instance, with hexamethylene bis-(carbamic acid choline bromide ester) of Exam le 5. This dru was used as curare substitute and mak s it possible to obtain great muscle relaxation methyl the l'esultlnfl olution, allow ng the without using high dosage of general anesthetics. It was reactlcn mlxtPre to stand "Hill clu'flternllatloil 18 administered by means of intravenous injection together plete, separatlng the l'esllltlng preclpltated Polymethylene bamic acid-B-dimethylamino ethyl ester) in an organic solvent, adding a quaternizing agent with a quaternizing with the anesthetic, such as thiopental sodium known to acid choline i f) mp of e abo e the trade as Pentothal Sodium or similar anesthetics. g e formula. and recrystalhzmg said compound; It is noteworthy and a distinct advantage of the muscle 2. In a process of producing a hexamethylene bis-(carrelaxant according to the present invention that both bamic acid choline ester compound) of the formula CH: /CH: H C HaBN-UHa-C Ht-O-C O-NH--(C Hahn-NH-C O-O--C Hr-C Ht-NqC Ht 32X" CH! CH:

solutions, the barbiturate solution and the hexamethylene wherein X is an anionic group selected from the group bis-(carbamic acid choline bromide ester) solution, can consisting of chlorine, bromine, iodine, and the p-toluene sulfonic a id. an n, th steps. ccmpri ng, adm x n fir.

bis-.(carbarnic acid chgline chloride ester) from the sol vent, and recrystallizing said quaternary compound from a water soluble organic solvent. b

4. In a process of producing hexamethylene bis-(car- 5 bamic acid choline bromide ester) of the formula CH H- aliphatic ketone, filtering off undissolved impurities, pre- 10 the steps comprising admixing fl-dimethylarnino ethanol,

cipitating the resulting hexamethylene bis-(carbarnic acidfi-dimethylamino ethyl ester) from. said solution by the addition of petroleum ether, separating the, precipitated ditertiary base from said solvents, dissolving said base in a water soluble lower aliphatic ketone, adding to said solution a quaternizing agent with a quaternizing methyl radical, allowing the reaction mixture to stand until quaternization is complete, separating the precipitated hexamethylene bis-(carbamic acid choline ester com 20 pound) from the solvent, and recrystallizing said quaternary compound from a water soluble organic solvent.

3. In a process of producing hexamethylene bis-(carbamic acid choline chloride ester) of the formula while cooling, to hexamethylene diisocyanate, allowing the reaction mixture to stand at room temperature until condensation is complete, dissolving the reaction product in a water soluble lower aliphatic ketone, filtering oif undissolved impurities, precipitating the resulting hexamethylene bis-(carbamic acid-B-dimethylamino ethyl es-t,

ter) from said solution by the, addition of petroleum ether, separating the precipitated ditertiary base from said solvents, dissolving said base in a water soluble lower aliphatic ketone, adding methyl bromide to said solution, allowing the reaction mixture to stand until quaternization is complete, separating the precipitated hexamethylene bis-(carbamic acid choline bromide ester) [rom OH: H

dissolved impurities, precipitating the resulting hexa- 3 methylene bis-(carbarnic acid-fl-dimethylamino ethyl ester) from said solution by the addition of petroleum ether, separating the precipitated ditertiary base from said solvents, dissolving said base in a water soluble lower aliphatic ketone, adding methyl chloride to said solution, 40

allowing the reaction mixture to stand until quaternization is complete, separating the precipitated hexamethylene 30 the solvent, and recrystallizing said quaternary compound from a W ter soluble organic solvent.

References Cited in the file of this patent UNITED STATES PATENTS 2,585,826 Olsen Feb. 12, 1952 2,683,167 Girod et al. July 6, 1954 2,703,810 Viard Mar. 8, 1955 OTHER REFERENCES Iwakura: Chem. Abstracts 44 (1950), 11106 f. Delaby et al.: Comp. Rend., v. 235 (1952), 376-7. Cheymol et al.: Comp. Rend., v. 235 (1952), 1711-13. 

1. IN A PROCESS OF PRODUCING A POLYMETHYLENE BIS-(CARBAMIC ACID CHOLINE ESTER) COMPOUND OF THE FORMULA 